


In which being nice to cats backfires on Aizawa

by Kosaji



Category: Kuroshitsuji | Black Butler, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: Aizawa Shouta | Eraserhead Loves Cats, Demon Sebastian Michaelis, Demon Summoning, Kuroshitsuji | Black Butler References, M/M, Summoning gone wrong
Language: English
Status: Completed
Published: 2019-10-08
Updated: 2019-10-08
Packaged: 2020-11-27 17:15:17
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,243
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20951990
Author URL: https://archiveofourown.org/users/Kosaji/pseuds/Kosaji
Summary: An interrupted summoning on the UA school ground brings Sebastian Michaelis and Aizawa together.Aizawa disapproves.Sebastian on the other hand is DELIGHTED upon finding a human that acts like a cat.





	In which being nice to cats backfires on Aizawa

**Author's Note:**

> I... don't know. Don't ask, just... don't ask.

Shouta works at a highschool. He learns through experience that sometimes, no matter HOW hard he tries, there is no getting around teenage stupidity.

Such as right now, as he stares down a small group from the support class, dressed in loose, billowing robes all tied together by his capture equipment.

“What is going on here?” Shouta asks, not because he wants to know, but because its his job.

He would rather NOT know why a bunch of kids decided that this weekend would be the perfect night to perform a satanic ritual instead of more important things. Like sleep.

One of the kids, a girl Aizawa vaguely remembers Maijima complaining about during a staff meeting, squirms furiously in her binds.

“Talk,” he says, tightening the capture weapon.

“We’ll talk, we’ll talk!” one of the students wheezes out.

“Shinji!”

“Look Fujiwara, it didn’t work! Just give it up and maybe we won’t get expelled!” Shinji says, squirming around to glare at the girl.

Fujiwara Satoko, Shouta remembers. Maijima had said she was brilliant at recreating historical weaponry. It looks like weapons aren’t the only historical thing she likes to dabble in. Fujiwara keeps struggling, trying to get closer to the star inscribed inside a circle that is drawn on the concrete in dark red. It’s not blood, otherwise these five students would be inside Nezu’s office with their homeroom teacher instead of dealing with Shouta.

“Enough,” Shouta sighs, closing his eyes and tugging the group firmly away from the circle. He releases his capture weapon and pins them all with an unimpressed look. “Who’s your homeroom teacher?” Best to just hand them off to someone else, he’s getting late for his patrol.

Its a mistake, as Fujiwara lunges for the circle. Her fire quirk flares, weaker than Todoroki’s but still enough to make him flinch, catching him off guard. Shouta blinks the dots out of his eyes and at the same time snaps his capture equipment in her direction.

It’s too late though, as Fujiwara has lit all the candles and cuts her finger. A drop of blood falls down into the center of the circle as Shouta pulls her away, and the candlelight flares. Shouta shoves the girl back with her classmates, standing in front of them as the flames grow to the size of a large bush before going out, leaving a puddle of wax at each point of the star. In the middle of the circle stands a man dressed in a black suit. Black hair with long chin length bangs frame a face with skin so pale it’s almost unnatural. Red eyes shine in the darkness as they look beyond Shouta to the silent children and then slowly back to him.

“Who the hell are you?” Shouta asks, ready to activate his quirk. The man smiles, slow and delighted as he gives Shouta a once over.

“Oh my,” the stranger breathes out, his voice low and dark. He takes a step out of the circle, eliciting screams from the children. Another step has their courage failing as Shouta hears them run away, still screaming their heads off.

At least they’ll catch someone’s attention, Shouta thinks, shifting his grip on his capture weapon, keeping his body between the intruder and the fleeing students.

They’re all still getting detention though.

“I didn’t think that answering the summons would have gotten me _this_,” Shouta jerks away from the hand coming towards his face. He lashes out with a fist only to have it caught in ice cold hands, the man not even looking as he twists Shouta’s hand away up and away. “This really is quite a surprise! A good surprise I assure you,” the man adds, tilting his head towards Shouta. 

Shouta fixes his face into his most deadpan stare. “Thanks,” he says, his other hand coming around to clap against the man’s ear. That hand is also caught and when Shouta tries to yank back and get distance he can’t move, held in place by the grip on his hands.

“Aizawa Shouta,” he freezes as the man purrs out his name, leaning into his pace with a sultry look in his red eyes. “You’re a rather interesting man, aren’t you?”

“Let go!” he growls, dropping to kick at the man’s legs. His hands are dropped as the man jumps, avoiding his kick and tackles Shouta to the ground, pinning his thighs down with his knees as his hands are caught up above his head.

“Now why would I do that?” the man asks, tilting Shouta’s chin up with his free hand.

_Erase_.

Shouta takes the chance and activates his quirk, but the man keeps smiling down at him, unperturbed as Shouta’s eyes start to ache. He struggles but nothing he does makes the man budge, and he’s quickly reaching the time limit for his quirk.

He blinks and the stranger just watches him, not making any other movements even as Shouta stops trying to escape.

“What do you want?” Shouta finally asks, fed up with being trapped on the cold ground. The man pulls back, still wearing that unnerving smile.

“I wasn’t going to answer the summoning you know.” Shouta freezes. There’s something heavy in the way man says summoning, something that makes the hair on the back of Shouta’s neck raise up. “With such a sloppy execution, it was almost an insult. But,” red eyes burn with a fire that Shouta can’t help but describe as unholy, “then I saw you.”

What the hell? Shouta starts squirming again, really not liking where this is going.

“You’re rather famous in our circles, you know?” The man continues, “It’s rather embarrassing that I would meet you like this, instead of greeting you properly. Though,” the man casts his eyes down looking down at him under half-lidded eyes, “I suppose you would be just as uncooperative. Part of your charm.”

Great, a stalker. “What are you?”

That smug, satisfied smile grows, revealing white teeth that gleam in the low light, catching on unnaturally sharp incisors that make Shouta more aware of just how vulnerable his neck is.

“I am a demon, call me Sebastian,” the man, no demon says leaning in, coming far too close for comfort-!

“Eraserhead!”

Shouta has never been so happy to have his eardrums assaulted by Present Mic’s quirk. Sebastian covers his ears with a grimace, looking rattled for once and Shouta takes the opening, twisting his hips to toss him off, jumping to his feet and putting some much needed distance between them.

Present Mic, Snipe and surprisingly All Might stand at ready, Present Mic already blasting another sound wave at Sebastian. Shouta grabs his scarf and not a moment too soon. Sebastian just waves his hand, physically batting aside Present Mic’s attack with a dark scowl. Shouta snaps his wrist and his scarf whips out, looping around Sebastian and pulling tight, binding his arms to his sides the same time Shouta activates his quirk, just in case. Somehow, despite all odds it works.

Sebastian looks surprised as the red glow abruptly fades from his eyes. He looks at Shouta with an unnervingly hungry stare before smiling and offering his surrender.

“So, you are a demon,” Nezu says, sipping his tea. Across from him, in one of the holding cells in the police department Sebastian smiles, even as he is surrounded not only by armed policemen but several pro heroes.

“Yes,” Sebastian confirms again, smiling like this is a normal tea party and he isn’t being interrogated.

“And you were summoned by a few of my students?”

“Not quite,” Sebastian says, leaning back in his chair, the multiple chains and cuffs wrapped around him jingling with every movement. “They did summon me, but I was not going to answer it. Summons from curious children really are nothing but a waste of time.” 

“And yet here you are.”

Shouta frowns from behind his scarf. So far Sebastian has been cooperative, letting himself be arrested and taken into custody. He still can’t shake the feeling of doom that has been following him though.

Especially since Sebastian keeps looking at him through the one way glass, even when Shouta changes places with Present Mic.

“So why did you answer the summons, Mr…”

“Michaelis.”

“Of course.” Shouta gives Nezu credit, keeping a straight face when a demon gives the ostentatious, foreign fake name takes effort. “Why are you still in this realm?”

Red eyes gleam, and Shouta gets a bad feeling as they look past Nezu and stare directly right at him.

Hours later Shouta is nursing a beer as Hizashi laughs at him.

“So, wait, wait,” Hizashi slaps his hand on the table, his own beer a safe distance away. “You once saved a demon cat, and it went around Hell singing your praises?” He takes one look at Shouta and starts laughing again. “Only you, man. Only you.”

Shouta just grumbles into his capture weapon and regards his mostly empty bottle. 

Apparently no good deed goes unpunished, and he only had himself to blame. 

“Did you know Mittens was a demon?” 

Nemuri snorts, slamming down another beer in front of him as she drops to the adjacent seat. “Shouta, I think you were the only one that cat actually liked, and it bit you half the time anyways.”

Shouta blinks.

"Of course no one knew she was a demon! Hell no one knew demons existed until this morning!" Nemuri throws her hands up, collapsing back against the couch.

Shouta grumbles and drowns the rest of his beer. He eyes the open case on the table, debating on whether he should drink another one. It was a school night, and it would be illogical- irresponsible even- for him to arrive at work with a hangover. 

“So how many other demon cats have you been secretly cozying up to?” Nemuri smirks over her bottle, jerking it safely out of the way as Mic bends over laughing. 

Screw it, he decides, cracking the tab decisively. The troublemakers can spend the day doing physical conditioning, Hound Dog owes him one. 

There is a glimpse of white teeth against black shadows out of the corner of his eye that he firmly ignores. The faster the demon gets bored of him the better.

Three days later, when the same demon is fussing over the bleeding cut under his eye as they are surrounded by the (unconscious) bodies of numerous villain he privately admits that it might be useful to have Sebastian around. 

Logical even, given how he had struck the Nomu down after it had thoroughly thrashed Shouta . 

“Tsk, that’s going to leave a scar,” Sebastian murmurs, dabbing at the edge of the wound lightly. His eyes burn faintly as they track the trails of red streaking down his face, expression too hungry to mean anything innocent. 

“Whatever, next time I’ll ask villains to avoid the face,” Shouta grunts, and freezes as Sebastian’s long cold fingers curl around his chin, keeping him in place as his pupils slit like a cat, irises glowing with malevolence. 

It says something about just how fucked up his tastes are when his stomach clenches and swoops out from under him as Sebastian pulls him closer, fingers firm and unyielding even as Shouta tries to yank his face away. 

“There will not be a next time,” the words are purred out against his lips, a promise burning between them that Shouta is too exhausted to navigate even as his lips tingle. “I believe that mouse offered a teaching position earlier.”

Shouta ’s eyes widen, a croaked “What?” said in alarm as Sebastian, that bastard, smiles and gets off the ground. He growls and a twist of his arm has the tatters of his capture weapon up and around the demon’s arm, holding him in place.

“Oi, what do you mean by that?” Shouta asks, stepping closer to where Sebastian is admiring the wrap of cloth around his arm like a woman admiring her engagement ring. The thought sends a shiver through him, and he immediately releases the demon with a snap of his wrist. Sebastian catches the capture weapon, bringing the ends up to his lips, parting them with a sigh when the capture weapon retracts back around his neck.

“Nedzu-sensei offered me a job. A teacher’s aide,” he smirks at Shouta , taking advantage of the clearly eavesdropping classroom of children that Shouta has inadvertently caught the attention of to raise his voice so that it also carried over to the less obvious but still eavesdropping adults. “I said I had some experience as a tutor, and he agreed that it might be the most unobtrusive use of my time here.”

Unobtrusive his ass, Nezu probably wanted to one up the police force by keeping a pet demon.

A pet demon that protected him and his charges, Shouta grudgingly admits, walking past Sebastian, his hands tucked into his pants as he goes to make sure all members of the class are accounted for. Sebastian falls into step behind him, dark eyes focused on the back of his neck, making him away of just how present Sebastian’s attention is.

It’s creepy. 

And kind of hot.

Shouta groans into the remains of his capture weapon as Sebastian chuckles knowingly behind him. 

Fine, maybe he won’t _mind_ being the catnip in this scenario.

He’s still going to make his opinion known to Nedzu. After he gets some sleep.

Without that dratted demon.

**Author's Note:**

> Spoiler : He goes home with that dratted demon.


End file.
